In order to increase operational efficiency, and thereby decrease fuel consumption, designers of gas turbine engines continually pursue ways to decrease component weight while maintaining resilience necessary for the operation of such engine. Fan blades are no exception.
One way gas turbine engine designers have utilized to reduce fan blade weight is by employing an open-cell reticulated metal foam core enveloped by an outer shell of a resilient second material that forms the airfoil. In one design, the outer shell is manufactured from a metal or metal alloy. In another design, the outer shell is comprised of one or more layers of composite material.
Such fan blade designs are not without complication. The void fraction of the open-cell reticulated foam utilized to manufacture such metal foam is commonly about ninety seven percent. While not necessarily conclusive, data suggests that the ligaments and nodes of metal foams created with the use of such high void fraction open-cell reticulated foams lack the strength and mechanical properties necessary for use in a fan blade. Accordingly, a need exists for modified, open-cell reticulated foams that can be used as a precursor to manufacture open-cell cell reticulated metal foams for a gas turbine engine fan blade. This disclosure is directed toward this end.